As the living standard improves and the economy blooms, more people living in cities use cars for their transportations and drive to work or go out for fun more often. In busy lanes, drivers have to follow the rules and regulations as set forth by traffic laws strictly to avoid car accidents. As specified in basic traffic laws and regulations, drivers should use the signal lights properly to indicate the position and the driving direction of their car to avoid car accidents.
To assure a safe driving condition, drivers have to turn on the headlights when driving in a dark area or at nighttime to provide sufficient light and remind drivers to watch out for the road conditions. From the description above, we know that headlights are absolutely important to cars, and thus related automobile manufacturers put up tremendous efforts on the development of the headlights. Some manufacturers build a light sensor in the headlight of a car, such that when we drive a car in a dark environment, the light sensor will automatically detect the darkness and supply a power source of the battery to the headlights for the illumination. On the other hand, when we drive a car in a bright environment, the light sensor will automatically detect the bright environment and disconnect the power source of battery, such that power will not be supplied to the headlights through the light sensor. Drivers can also turn on the headlights manually for the illumination, and thus the light sensor can bring tremendous convenience to the driver, and thus the light sensors are used and installed in cars extensively.
However, if a driver turns on a headlight manually while driving the car, the driver may forget to turn off the headlight after parking the car, and the power source of the battery is supplied continuously to the headlights until the power source of battery runs out, and the driver cannot start the car again since the power source of the battery is exhausted. It is good news for consumers to hear that related automobile manufacturers provide a device for turning on the headlights automatically when a car is started, and turning off the headlights automatically when the engine is turned off.